This application claims benefit of Japanese Applications No. Hei11-368191 filed in Japan on Dec. 24, 1999 and No. Hei11-368194 filed in Japan on Dec. 24, 1999, the contents of which are incorporated by this reference.
1. Field of the invention
The present invention relates to a frame member supporting structure of a lens barrel having plural movable frame members.
2. Related Art Statement
In recent years, compact cameras have been reduced in size and employ a high-magnification zoom function and other novel functions. Corresponding to these trends, various types of moving frame retracting mechanisms of the lens barrel have been proposed.
For example, in a lens barrel employing the moving frame positioning method disclosed in Japanese Patent Application Laid-Open No. HEI4-52629, a bar-like guide member for supporting a third moving frame slidably with respect to first and second moving frames is employed. The bar-like guide member is fixed to the first or second moving frame such that an end or both ends of the bar-like guide member are held by the first or second moving frame and the third moving frame is supported slidably by the guide member.
Because in the aforementioned lens barrel, an end of the bar-like guide member or both ends thereof are fixed to a movable frame, a space around that fixing portion becomes a waste space. At the same time, this is an obstacle for a disposition space for other structural members. In the case of a cantilever structure in which an end of the bar-like guide member is supported, the span of the bar-like guide member is long, so that the defection thereof is increased. Therefore, it is difficult to make a thin bar-like guide member, which is an obstacle against reduction of the size of the lens barrel.
In the lens barrel disclosed in the aforementioned Japanese Patent Application Laid-Open No. HEI4-52629, a fourth moving frame is supported such that it is capable of being advanced or retracted relative to the third moving frame. Thus, two other bar-like guide members are provided additionally. As a result, to hold four moving frames such that they are capable of being advanced or retracted, four bar-like guide members are disposed. These guide members are fixed completely to any of the moving frames. Thus, a very highly accurate configuration and dimension are demanded for the moving frame and the guide members, thereby leading to increase of part cost. Further, because the quantity of the guide members is large, there is also such a problem that it takes long for assembly work.
The present invention has been achieved to solve the above-described problems and an object of the invention is to provide a lens barrel having an effect of reducing part cost, which is easy to assemble, which an excellent space efficiency and which enables a reduction of the size.
The lens barrel according to an aspect of the present invention includes a first frame, a second frame, a third frame, and a first supporting member both ends of which are fixed to the second frame such that they are exposed. The first and third frames are supported by the first supporting member.
Further, a lens barrel according to another aspect of the present invention has a first frame, a second frame, a third frame, a fourth frame, a first supporting member both ends of which are fixed to the second frame such that they are exposed and a second supporting member which is supported by the first frame and third frame. The first frame and the third frame are supported by the first supporting member and the fourth frame is supported by the second supporting member.
Other features and benefits of the present invention will be apparent from the following description.